1. Field of the Invention
The present invention relates in general to transducers, and more particularly to acoustic transducers. The present invention also relates to a compact transducer capable of radiating acoustic energy from large magnified piston displacements through a radial drive arrangement.
2. Background and Discussion
An orthogonal drive electro-mechanical apparatus is shown in my earlier granted U.S. Pat. Nos. 4,845,688, and 6,654,316 B1. This transducer construction uses lever arms or shells, which are connected to active piezoelectric, electrostrictive or magnetostrictive elements to drive one or two pistons with amplified motion. Another orthogonal electro-mechanical apparatus is shown in another of my earlier granted patents, namely, U.S. Pat. No. 4,754,441 where a bending motion of the drive system is used to move a flextensional shell in a mode of oscillation. Still another one of my earlier patents is U.S. Pat. No. 4,742,499, which shows four orthogonal electro-mechanical bars driving four curved plates to produce a radial amplified motion of the plates thus providing acoustic radiation into the medium in contact with the plates (or shells).
It is a general object of the present invention to provide a transduction apparatus, which is of the general type described in my prior art patent, U.S. Pat. No. 4,742,499 but which is of improved construction and performance using a radial piston arrangement for the acoustic radiation. The motion of the piston arrangement of the present invention is not orthogonal to the motion of the drivers as in the prior art U.S. Pat. Nos. 4,845,688 and 4,754,441.
Another object of the present invention is to provide a magnified-motion multiple-piston transduction apparatus driven by radial extensional electro mechanical means.
A further object of the present invention is to provide an improved acoustical matching means for broadband operation at low frequencies through the magnified motion of the multiple piston transduction apparatus.
A still further object of the present invention is to provide a bender mode driven electro mechanical means for exciting other modes such as the dipole mode or quadrupole mode.
Still another object of the present invention is to provide a three dimensional arrangement for exciting the fundamental mode and three orthogonal dipole modes in the form of a tri-axial projector or receiver.
All of the above mentioned patents are hereby incorporated by reference in their entirety.